[6]-Shogaol Induces Apoptosis of Murine Bladder Cancer Cells.

Background/aims: Bladder cancer is considered one of the most aggressive neoplasms due to its recurrence and progression profile, and even with the improvement in diagnosis and treatment methods, the mortality rate has not shown a declining trend in recent decades. From this perspective, the search and development of more effective and safer therapeutic alternatives are necessary. Phytochemicals are excellent sources of active principles with therapeutic potential. [6]-Shogaol is a phenolic compound extracted from the ginger rhizomes that has shown antitumor effects in a wide variety of cancer models. However, there is no record in the literature of studies reporting these effects in models of bladder cancer. Thus, this study aimed to investigate the in vitro cytotoxic and pro-apoptotic potential of [6]-Shogaol against murine bladder cancer urothelial cells (MB49).

Methods: The cytotoxic effects of [6]-Shogaol on cell viability (MTT method), cell morphology (light microscopy), alteration of proliferative processes (clonogenic assay), oxidative stress pathway (levels of reactive oxygen species) and the induction of apoptotic events (flow cytometry and high-resolution epifluorescence imaging) were evaluated in murine urothelial bladder cancer cell lines (MB49), relative to non-tumor murine fibroblasts (L929).

Results: The results showed that [6]-Shogaol was able to induce concentration-dependent cytotoxic effects, which compromised cell viability, exhibiting an inhibitory concentration of 50% of cells (IC50) of 146.8 µM for MB49 tumor cells and 236.0 µM for L929 non-tumor fibroblasts. In addition to inhibiting and altering the proliferative processes if colony formation, it presented pro-apoptotic activity identified through a quantitative analysis and the observation of apoptotic phenotypes, events apparently mediated by the induction of nuclear fragmentation.

Conclusion: The data presented suggest that [6]-Shogaol has a higher concentration-dependent cytotoxic and apoptosis-inducing potential in MB49 cells than in L929 fibroblasts. These results may contribute to the development of therapeutic alternatives for bladder cancer.